1. Field of the Invention
The present invention relates to an image display which displays an image by driving, for example, a self-luminous element such as an organic EL (Electro Luminescence) element and an image display method.
2. Description of the Related Art
In recent years, in the field of displays displaying an image, displays using, as light-emitting elements of pixels, current drive type optical elements of which light emission luminance changes depending on the value of a current flowing therethrough, for example, organic EL (Electro Luminescence) elements have been developed for commercialization. Unlike a liquid crystal element or the like, the organic EL element is a self-luminous element. Therefore, in a display (an organic EL display) using the organic EL element, a light source (a backlight) is not necessary, so compared to a liquid crystal display needing a light source, a reduction in the profile of the display and an increase in the luminance of the display are allowed. In particular, in the case where the display uses an active matrix system as a drive system, each pixel is allowed to continuously emit light, and a reduction in power consumption is allowed. Therefore, the organic EL display is expected to become a mainstream of next-generation flat panel display.
The organic EL element is a current drive type light-emitting element, and is an element allowed to adjust gradation by controlling the amount of a current flowing therethrough. However, the organic EL element has a characteristic of being degraded according to its light emission amount and its current-carrying time, and luminance of an organic EL element in an advanced stage of degradation relatively declines, compared to luminance of an organic EL element in a less-advanced stage of degradation. On the other hand, luminance of a displayed image is not uniform in all pixels, so degradation in organic EL elements in all pixels are not also uniform. Therefore, a decline in luminance according to degrees of degradation in the organic EL elements occurs in a display region.
This phenomenon is called “burn-in”, and in particular, when a still image is displayed on a display screen for a long time, burn-in easily occurs. To accurately correct “burn-in”, it is necessary to correctly detect actual degradation states of organic EL elements. As one solution to this issue, for example, a large number of methods of correcting a picture signal with use of a degradation amount of each pixel derived from an accumulated light emission time have been reported, for example, as described in Japanese Unexamined Patent Application Publication No. 2007-206463.